Binary Millisecond Pulsar Discovery via Gamma-Ray Pulsations

TL;DR

This paper reports the discovery of a 2.5-millisecond gamma-ray pulsar, PSR J1311-3430, in a tight 93-minute orbit, using a computationally intensive blind search of Fermi LAT data, confirming a long-standing gamma-ray source mystery.

Contribution

First detection of a millisecond pulsar via gamma-ray pulsations using a blind search method, revealing a new class of ultra-compact binary pulsars.

Findings

Discovered a 2.5-ms gamma-ray pulsar in a 93-minute orbit.

Confirmed the nature of a previously unidentified gamma-ray source.

Demonstrated the effectiveness of blind gamma-ray pulsar searches.

Abstract

Millisecond pulsars, old neutron stars spun-up by accreting matter from a companion star, can reach high rotation rates of hundreds of revolutions per second. Until now, all such "recycled" rotation-powered pulsars have been detected by their spin-modulated radio emission. In a computing-intensive blind search of gamma-ray data from the Fermi Large Area Telescope (with partial constraints from optical data), we detected a 2.5-millisecond pulsar, PSR J1311-3430. This unambiguously explains a formerly unidentified gamma-ray source that had been a decade-long enigma, confirming previous conjectures. The pulsar is in a circular orbit with an orbital period of only 93 minutes, the shortest of any spin-powered pulsar binary ever found.